const fs = require('fs');
const http2 = require('http2');
const jwt = require('jsonwebtoken');

const token = jwt.sign(
  {
    iss: 'APPLE-TEAM-ID',
    iat: Math.round(new Date().getTime() / 1000),
  },
  fs.readFileSync('./myapp_apns_key.p8', 'utf8'),
  {
    header: {
      alg: 'ES256',
      kid: 'P8-KEY-ID',
    },
  }
);

const IS_PRODUCTION = false; // TODO: your check
const client = http2.connect(
  IS_PRODUCTION ? 'https://api.push.apple.com' : 'https://api.sandbox.push.apple.com'
);

const deviceToken = 'device token grabbed cient-side';

const headers = {
  ':method': 'POST',
  ':scheme': 'https',
  'apns-topic': 'YOUR-BUNDLE-IDENTIFIER', // TODO: your application bundle ID
  ':path': '/3/device/' + deviceToken,
  authorization: `bearer ${token}`,
};

const request = client.request(headers);

request.setEncoding('utf8');

request.write(
  JSON.stringify({
    aps: {
      alert: {
        title: "\uD83D\uDCE7 You've got mail!",
        body: 'Hello world! \uD83C\uDF10',
      },
    },
  })
);

request.on('response', (headers, flags) => {
  for (const name in headers) {
    console.log(`${name}: ${headers[name]}`);
  }
});

let data = '';
request.on('data', chunk => {
  data += chunk;
});

request.on('end', () => {
  console.log(`\n${data}`);
  client.close();
});

request.end();